calcyman wrote:Yes, there are even configurations which fire an infinite sequence of distinct spaceships.

I need an example. Like, now. This sounds amazing.

It's probably less exciting than you think. We know such a thing exists, and we know how to make one, but we haven't done it yet. The plan that I assume is being alluded to above involves creating a pattern that fires UC-based spaceships, with each one being extended trivially to be slower than the last by moving one section of the ship a little bit farther away from the rest of the ship.

On second thought, though, it might be possible to make such a gun that is at the very least interesting to watch working. A pattern firing ever slower caterloopillars would probably be quite a complicated gun, as it would essentially have to run the algorithm used to generate those spaceships and then construct the design it calculated. Might be too big and bulky to run in Golly, but it would certainly be an impressive demonstration of the technology we have so far.

But slowing speed isn't the only way to shoot infinitely many distinct ships. All you need to do is fire longer and longer chains of interacting MWSS or HWSS. Can't provide an example right now, but it's likely somebody has already done this, so I guess my second sentence of this post is probably a bit inaccurate...

Probably the most attainable construction of such a pattern would fire those c/2 ships that have a burning fuse reaction behind them, with longer and longer fuses each time just made by appropriate delay on the construction process. There is a grammar for arbitrarily long c/2 ships and whether or not they haven't all been explicitly shown constructible it seems pretty simple to construct them.

cis- on the same sidetrans- on the other sideortho- adjacentpara- opposite

That said, it's often not easy to understand how to apply these terms to come up with a description of a still life or oscillator. And the other direction -- visualizing the object from the description -- is quite often not possible.

Very often the nomenclature seems pretty arbitrary to me, like the difference between trans-mirrored and trans-rotated R-bees. You just plain won't know all the shapes for sure in advance, if you only have the description and haven't memorized the objects.

The boat-with-tail distinction makes some sense to me -- the extra bit is either on the same side as the connection to the tail, or on the other side. Even there, ortho-boat-with-tail and para-boat-with-tail seem like better analogies.

I don't understand the extension to loaf-with-tails at all. It seems to be the key part of the loaf is opposite (trans) in the cis-loaf-with-tail, and nearby (cis) in the trans-boat-with-tail. If someone can explain that clearly with nice short words, I'll happily put the explanation in the Life Lexicon -- maybe a general summary of uses of cis- and trans-, at least?

Anyway, the name assignments probably made sense to somebody when they were first invented, and those are definitely the names now. A different naming convention would probably make equally little sense to just as many people. The analogy is always going to be a little bit strained between organic chemistry (five- and six-atom carbon rings) and Conway's Life objects, which might have fourfold or eightfold symmetry.

dvgrn wrote:I don't understand the extension to loaf-with-tails at all. It seems to be the key part of the loaf is opposite (trans) in the cis-loaf-with-tail, and nearby (cis) in the trans-boat-with-tail. If someone can explain that clearly with nice short words, I'll happily put the explanation in the Life Lexicon -- maybe a general summary of uses of cis- and trans-,

To me it is pretty natural. In the cis configuration it looks like the loaf (maybe the center of mass?) is on the same side of the tail, which is down. If there is a way to calculate the "standard deviation" of the cells, then I think it can be defined formally.

Whoa. I know you have probably moved on from that ship to other things, but I suddenly have a lot of questions about the ship:1. What is it called?2. How was it discovered?3. Are there any known guns that can produce it (I'd imagine they'd be pretty big or have to move constantly)?

Gamedziner wrote:Whoa. I know you have probably moved on from that ship to other things, but I suddenly have a lot of questions about the ship:1. What is it called?2. How was it discovered?3. Are there any known guns that can produce it (I'd imagine they'd be pretty big or have to move constantly)?

It comes from a pretty explosive rule, and there are no smaller gliders, so I'm not sure if there would be any (small enough) guns for it (patterns also tend to stick to each other in this rule, so the ship would be kind of hard to seperate)

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How many other small blinker puffers are there? Here is my microscopic stamp collection, complete with horribly drawn numbers:

muzik wrote:1: Could a c/12 diagonal (corder)ship smaller than the current record holder 134-cell Cordership exist?

It's certainly possible. There isn't even any way to definitively rule out some really unlikely way to burn the debris from a block-laying switch engine cleanly at a speed of exactly c/12... so we can't definitively rule out the possibility that the true record-smallest Cordership is just one switch engine plus some trailing junk.

It seems somewhat more likely -- but still not terribly likely -- that an "orbit" could be found where the debris from two interacting switch engines could be burned cleanly. If we wanted to give a really good shot at finding that, we could try setting up something along the lines of the script that codeholic wrote to find the p36 fuse for pufferfish exhaust, starting with different randomized pairings of switch engines with a block of random soup a short distance behind them. Run millions of those through a hacked apgsearch, and see if something new and interesting ever comes out.

muzik wrote:What is the highest "dimension" of an infinite growth pattern created?

There isn't really any limit to this as far as I'm aware, though it must be remembered that the actual long-term population growth rate in an n-dimensional CA cannot exceed nth degree polynomial growth (2nd degree is quadratic, 3rd degree is cubic, etc). But we can still make things that act like what you've described. For example, I found a quadratic-growth MMMM 'super-breeder' in an old rule known as aurora19 a few years back. I'm sure there's some other examples out there.

Late reply I know, so does this mean one cannot exist in normal Life (but can in other specialised cellular automaton)?

What I was thinking for an example, would be something similar to breeder 1, which is a Gosper glider gun producing puffer, but have the guns spaced out a bit more. Then the thing that creates the breeders would position them so that the created Gosper glider guns would fire through the gaps in each other. However, this would probably only work twice before turning into a massive mess.

So, I take it it's not possible to build a moving pattern that creates moving patterns which create rakes?

muzik wrote:So, I take it it's not possible to build a moving pattern that creates moving patterns which create rakes?

It probably is, but the final rakes' output cannot last forever; the output must be destroyed eventually to maintain a quadratic growth rate at most.

Yeah, there's no technical difficulty in building such a pattern -- except for dying of boredom or frustration in the design stage. It's just that when you run the pattern, you might get a massive mess after a while, as you suggested.

For example, an East-moving object could build regularly spaced North-moving rake builders, each of which would start building regularly-spaced West-moving rakes. So far so good! It's not a problem that more and more rakes will be created simultaneously, as time goes on -- they're all traveling West at the same speed, so they'll stay out of each other's way.

The problem is that no matter which cardinal or intercardinal direction you choose for the rakes' output, that output is going to start hitting other rakes, sooner rather than later. Only the rakes on the outermost edge(s) will be safe from other rakes, depending on the geometry.

It would probably be possible to build in to each rake some defenses against other rakes' output -- but then any suppressed rakes don't add anything to population growth after a while.

dvgrn wrote:For example, an East-moving object could build regularly spaced North-moving rake builders, each of which would start building regularly-spaced West-moving rakes. So far so good! It's not a problem that more and more rakes will be created simultaneously, as time goes on -- they're all traveling West at the same speed, so they'll stay out of each other's way.

Wait, wouldn't that mean you could add in diagonal or oblique rakes, rakes of rakes, etc?

Yeah, I could build one. But it would be a big self-constructing and self-destructing thing.

At least it would give an (unreasonable) upper bound of some sort. So then the question becomes, what is the smallest such statorless rotating oscillator?

... Unfortunately having an upper bound doesn't make it an answerable question. The smallest one could be quite small, findable by running a hacked apgsearch for a few decades... or the smallest one could actually be a hyper-optimized self-constructing thing that encodes its own pattern in some clever way.

There's no way to know, unless it turns out that the smallest one fits in an MxN box, with M and N small enough that technology eventually advances to allow us to exhaustively search the space.

Yeah, I could build one. But it would be a big self-constructing and self-destructing thing.

At least it would give an (unreasonable) upper bound of some sort. So then the question becomes, what is the smallest such statorless rotating oscillator?

... Unfortunately having an upper bound doesn't make it an answerable question. The smallest one could be quite small, findable by running a hacked apgsearch for a few decades... or the smallest one could actually be a hyper-optimized self-constructing thing that encodes its own pattern in some clever way.

There's no way to know, unless it turns out that the smallest one fits in an MxN box, with M and N small enough that technology eventually advances to allow us to exhaustively search the space.

All hail the almighty universal constructor argument.

If you think about it, the phoenix family could be considered statorless and rotating, but I'm not too sure about that. To narrow it down: a rotating, statorless oscillator whose bounding box expands and contracts to a certain degree.

I read a couple of days ago about a pond and block collocation that could eat HWSS xor MWSS, but I don't remember how it was. I have already tried looking for it on LifeWiki, but since it was neither a still life nor a pseudo-still life or any notable pattern per se, my attempts have been useless. Could someone remind me of how it was?

Rhombic wrote:I read a couple of days ago about a pond and block collocation that could eat HWSS xor MWSS, but I don't remember how it was. I have already tried looking for it on LifeWiki, but since it was neither a still life nor a pseudo-still life or any notable pattern per se, my attempts have been useless. Could someone remind me of how it was?

Brice Due called it a "honeybit buffer", because of the ability of the same small constellation to store information -- set with a glider, test or reset with an LWSS: